Printing device with zero suppressing means



H. GELLING Dec. 7, 1965 PRINTING DEVICE WITH ZERO SUPPRESSING MEANSFiled March 28, 1963 5 Sheets-Sheet 1 Dec. 7, 1965 H. GELLING PRINTINGDEVICE WITH ZERO SUPPRESSING MEANS 5 Sheets-Sheet 2 Filed March 28, 1963H. GELLING Dec. 7, 1965 PRINTING DEVICE WITH ZERO SUPPRESSING MEANS 5Sheets-Sheet 5 Filed March 28, 1963 United States Patent 3,221,644PRINTING DEVICE WITH ZERO SUPPRESSING MEANS Helmnt Gelling, Dietlikon,Zurich, Switzerland, assignor to Precisa AG, Rechenmaschinenfabrik,Zurich, Switzerland Filed Mar. 28, 1963, Ser. No. 268,646 Claimspriority, application Switzerland, Apr. 5, 1962, 4,164/62 2 Claims. (Cl.101-93) The present invention relates to printing devices forcalculating machines comprising so-called live bridges preventing theprinting of zeros on all decade positions higher than a decade positionadjusted to a non-zero figure, while the zeros at lower decade positionsare printed.

The live bridges of known printing devices of the kind referred to areformed by abutments and counter-abutments provided on looking levers,which are provided for this special purpose and are arranged side byside, so as to be capable of locking the printing mechanisms associatedwith various decimal positions. The numerous components required forthese known live bridges, such as locking levers, springs etc. arecomparatively expensive and are moveover required to be produced inpractice extremely accurately, namely with tolerances of only 0.01 to0.02 millimetres.

The invention has the object of providing a printing device of the kindreferred to which dispenses wtih additional components constituting theabutments and counterabutments of said live bridges.

It is another object of the present invention to provide a printingdevice of the kind referred to which allows substantially widertolerances than hitherto permissible.

With these and other objects in view which will become apparent laterfrom this specification and the accompanying drawings, I provide aprinting device, for calculating machines comprising in combination: afixed frame, a plurality of printing mechanisms comprising type membershaving types to be printed, adjustment means adjusting said type membersto a selected type, abutments and counter-abutments provided on saidprinting mechanism, said abutments and counter-abutments forming a livebridge preventing the printing of Zeros for all decade positions higherthan the first non-zero decade position, said abutments andcounter-abutments being integral with components required for thefunctioning of said printing mechanisms anyway.

Said type members may be of circular arc shape, or type wheels, in anycase carrying the type characters 0, 1, 2 9 to be printed.

These and other features of my said invention will be clearly understoodfrom the following description of two embodiments thereof given by wayof example with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a printing device of a calculatingmachine only the printing mechanism of six decade positions being shown;

FIG. 2 is a side elevation of one of the printing mechanisms accordingto FIG. 1,

FIG. 3 is a perspective part view of another printing device, and

FIG. 4 is a longitudinal cross-sectional view of the printing mechanismshown in FIG. 3.

In the drawings, and more in detail, attention is first directed toFIGS. 1 and 2 wherein there is shown a printing mechanism for anaddition and similar machines of a conventional type which, for example,is provided with twelve mechanisms 1 arranged in side by side relationeach of which is intended to print a number of a predetermined decimalposition. However, only the printing mechanisms 1 associated with thesix highest decimal positions are partially illustrated in FIG. 1. Inthe following the parts of a single printing mechanism 1 and itsarrangement in the frame of the machine is described. An axle 2 (FIG. 2)aflixed to the not shown frame of the machine has pivotally mountedthereon a rocking lever 3 which has its lower end portion shaped toprovide an arcuate rack bar section 3a. A type lever 5 is pivotallyconnected with a downwardly extension 5a at 4 to the rocking lever 3.The type lever 5 is provided with an arc-shaped sector 6 on which ismounted ten printing characters or types 7 to print the numerals 0, 1,2, 3 through 9 on a suitable sheet of paper (not shown) supported on theroller platen 8.

A control bar comprising a toothed rack bar 9 whose teeth 10 areindicated by the pitch line only, is in mesh with a gear wheel of thecalculating mechanism (not shown). The rack bar 9 is slidably guidedlongitudinally in the conventional manner on a pair of bars 11 and 12arranged in transverse fixed relation to the frame. The rack bar 9 isprovided with an abutment formed by a pin 13 with which one arm 14 ofthe rocking lever 3 is maintained in contactual engagement by means of atension spring 15, the ends of which are affixed to hook-shapedprojections 16 and 17 on the arm 14 and on the toothed rack bar 9,respectively. Another spring 18 is attached to the lower end of the arm14 of the rocking lever 3 to yieldingly urge the same in acounterclockwise direction about the axis of the axle 2 and therebymoves the raclg bar 9 in a direction toward the right owing to theprovision of the abutment 13. A rod 19 which is moved transversely toand fro in the usual manner in the direction of the double arrow 20 isadapted to tension the springs 15 and 18 when the rod 19 is moved towardthe left. Formed on the left hand end of the rack bar 9 is a projection21 forming a shoulder which upon movement of the rod 19 in a directiontoward the right abuts the lower end of a pin 22 reciprocably mounted ina pin box of a conventional type and which corresponds in position to anumber character introduced into the box by means of the usual keyboard(not shown). The pin box and keyboard of conventional calculatingmachines are well known in the art and by way of example attention iscalled to the United States Patents Nos. 2,346,265 and 2,975,971.

The rack bar 9 is illustrated in FIGURE 2 in full line, and in thatposition, the pin 22 corresponding to the 0 character which has beenentered, while the dash-dotted line position of the mechanismcorresponds for example to the adjustment or setting of the pin 22 tothe 5 position.

A series of hammers 23, one for each printing mechanism I, is supportedin the mechanism for reciprocation to and fro in a longitudinaldirection. Each of the hammers is provided with a slot 24 adjacent oneend which receives a rod 25 suitably afiixed to the frame. A tensionspring 26 is connected to the other end of each hammer 23 to yieldinglyurge the same in a direction toward the right and to resist movement ofthe hammer 23 when the same is moved in a direction toward the left bythe rod 25 when the same is moved transversely by suitable settingmechanism on the frame (not shown). A trigger bar 27 comprising acircular rod with a radial vane thereon is pivotally mounted in theframe about a fixed axis, and in the position illustrated in FIG. 2engages with the outer edge of its vane a shoulder 28 provided on theright hand end of each hammer 23 so that the hammers will remain intheir tensioned positions when the rod 25 is transversely moved in adirection toward the right. i

Formed on the right hand end of each hammer 23 (FIG. 2) is a projection29 which protrudes at right angles thereto and projects into an arcuateslot 30 of the type lever 5. It will be seen, that depending upon theposition into which the rack bar 9 is shifted which in turn depends uponthe number character adjusted or set into the mechanism by means of theadjustment pin 22 the rocking lever 3 will assume a predeterminedposition and consequently the type lever will be rocked since it ispivotally attached to the rocking lever at 4 and guided on the ham mer23 at its end 29, thus, the printing type corresponding to the numbercharacter entered in the machine is pre-set and moved into the startingposition for printing. When the trigger bar 27 is rocked about its fixedaxis in a clockwise direction, the hammer 23 will follow the pull forceexerted by the spring 26 and the corresponding type lever 5 will berocked about its pivot pin 4 in a clockwise direction and forciblyprojected in the direction to ward the platen 8 and will print thepreset number character on the paper thereon.

Each of the twelve printing mechanisms would thus print a number whenthe trigger bar 27 is rotatably moved out of engagement with theshoulder 28, so that for example the following number would be printed:000002389024. The printing of the five zeros ahead of the number to beprinted, i.e. ahead of the highest decade position not occupied by azero, however, is undesirable, and in order to prevent this printing aso-called live bridge 31 (FIG. 1) is provided. This live bridge 31consists mainly of bridge elements 32 constituting abutments which areprovided on one end of the hammers 23. The abutment point of each bridgeelement 32 is designated with 33 and lies in the plane of movement of acounter-abutment stop edge 34 provided on an adjacent hammer 23 of alower decade position. In the present embodiment the bridge elementconsists of a lug 32 turned at an angle of 90 from the upper edge of apiece of sheet metal forming the body of the hammer 23, while thecounter-abutment edge 34 is formed by the left-hand upper portion of theedge of a recess 35 (FIG. 2) provided in the hammer 23 of the sheetmetal-piece. Obviously the terms abutment and counter-abutment could beinterchanged.

When the printing mechanism 1 is set and adjusted to the printing of an0 i.e. when the same is in the position shown in FIG. 2 in full lines,the bridge element 32 on one of the hammers 23 rests on a projection 36of the rocking lever 3, when the rocking lever 3 has been turned into aposition corresponding to any other figure than 0, the lug 32 cannotfollow up the projection 36, but reaches the position 32, which isdetermined by the hammer falling by gravity or dropping on the yoke 37of a loop 38'. This position of the hammer is indicated in chain-dottedlines in FIGURE 2 and is denoted 23'. Above the hammer of the highestdecade position, which in FIG. 1 is designated with 23", there isarranged an element 33 attached to the machine frame, of which in thepresent context a downwardly projecting projection 39 is of interest.This projection 39 lies immediately in front of the counter-abutmentedge 34 of the hammer 23", when the latter is adjusted to 0.

In FIG. 1 the hammer 23 and the next two hammers 23 and 23 are adjustedto 0 while the fourth hammer is adjusted to another figure and the fifthand sixth again to 0. When the trigger bar 27 is now rotated and itsvane releases the shoulders 28, on the hammers the hammer 23" cannotyield to the pull of the associated spring 26 (see FIG. 2), because itis arrested by the projection 39 fixed to the frame and disposedopposite the counterabutment edge 34". Since the first hammer 23" doesnot move, its bridge element 32" holds the second hammer back at thepoint 33" by its counter-abutment edge 34; likewise, the bridge element32 of the second hammer 23 detains the third hammer 23. The fourthhammer 23, which is not adjusted to 0, and accordingly is in the loweredposition 23' (see FIG. 2), is not however detained by the bridge element32 of the third hammer 23, since this bridge element 32 is positionedabove the counter-abutment edge of the fourth hammer. The fourth hammeris accordingly pulled to the right by its spring 26, whereby one of theprinting types 7 adjusted to its desired position by type lever 5 isforcibly projected against the paper sheet on the platen 8 by the spring26 and prints e.g. a number 3. The bridge elements 32 of the fourth andfifth hammers are in contact with the fifth and sixth hammers,respectively, which are both in the 0 position. Nevertheless the fifthand sixth hammers are not detained, since the fourth hammer beingprojected for producing an impact; the two zeros following the number 3on the right hand side are accordingly printed. Likewise all otherfigures farther to the right are printed by the further six printingmechanisms (not shown).

The spacing between the type 7 which is in a position ready for printingand the surface of the platen 8 amounts, as usual, to about 6millimeters or more. When the design dimension of the play s between thebridge element 32 at the point 33 and the counter-abutment edge 34amounts e.g. to 0.2 millimeter and a tolerance of 0.1 millimeter isallowed for this play in the worst case, namely when the play s for alltwelve bridge elements 32 has the highest permissible magnitude of 0.3millimeter, and when all digits are adjusted to zeros, the hammer 23 ofthe unit decade position may move towards the platen 8 a distance of 11O.3:3.3 millimeters when released by the trigger bar 27, so that it isstill arrested at a distance of 2.7 millimeters away from the platen.The magnitude of 3.3 millimeters, which denotes the limit distance ofthe live bridge 31 is considerably larger than that of the live bridgesof conventional mechanisms, the components of which have to be producedin practice with tolerances of only 0.0-0.02 millimeter. The advantageof a larger tolerance is of the greatest importance for the production,quite apart from the very great advantage, that the bridge elements 32are each integral with one of the hammers 23, while the elements of thelive bridges hitherto-as mentioned hereinabove-are provided on separatelevers, which block the movement of the type levers and are pivotallymounted on an axle fixed to the frame, and loaded individually bysprings. It is clear that in principle even a limit distance exceeding3.3 millimeters, say of 5 millimeters, would be permissible.

In the FIGS. 3 and 4 a printing mechanism is illustrated which isprovided type wheels instead of areshaped type carrying sectors, wherebyonly parts of the printing mechanisms 40 of the four highest decadepositions are illustrated. Each printing mechanism 40 has asubstantially vertically disposed type lever 41 which is pivotallymounted with its lower portion on an axle 42 fixed to the frame. On theupper portion of the type lever 41 a type wheel 43 is rotatably mounted,which has a spur gear 43a (FIG. 4) in mesh with a gear wheel 44, whichis likewise rotatably mounted on the type lever 41. On the type lever 41a further gear wheel 54 (FIG. 4) is rotatably mounted, which meshes onthe one hand with the gear wheel 44 and on the other hand with a toothedrack 9a corresponding to the toothed rack 9 of FIG. 1. On a hook 45 ofthe type lever 41 a tension spring 46 is attached, which when tensionedtends to turn the type lever 41 about the axle 42, so that a typeadjusted on the type wheel 43 hits the platen 8 or the paper arrangedthereon. The members serving for tensioning the springs 46 of theprinting mechanisms are well known and accordingly have not beenillustrated. Likewise a trigger bar 56 corresponding to the trigger bar27 of the form of the invention shown in FIGS. 1 and 2 and cooperatingwith the lower ends of angle levers 41a pivoted at 41b to the upper endsof the type levers 41 is employed as shown in FIG. 4. In FIG. 3 it isassumed that the trigger bar 56 has released the type levers: 41, butonly the two type levers illustrated on the left hand side of FIG. 3 areturned towards the platen 8 under the bias of their springs 46 andthereby each print a numeral 1, while the two type levers illustrated onthe right hand side, ie of the highest and next highest decadepositions, whose type wheels 43 are adjusted to 0, have not or nearlynot at all moved owing to the live bridge 47 to be explainedhereinafter.

This bridge is composed of abutments 48 provided on the type levers 41and of counter-abutments 49 provided on-the gear wheels 44. The abutmentis formed by a lug 48 extending laterally towards the left from themargin of the type lever 41, while the counter-abutment consists in atongue 49 cut or punched out of the body of the gear wheel 44 and turnedup towards the right. The tongue 49 of the gear wheel 44" of the typelever 41" of the highest decade position cooperates with an abutment 50,which is provided on a frame element 51.

The tongues 49 are arranged on the gear wheels 44 in such a positionthat upon adjustment of the associated type wheel 44 to its 0 positionthey are disposed in rear of the lug 48 of the adjacent type lever 41 ofthe next highest decimal position while the tongue 49 of the highestdecade position is disposed in rear of the the abutment 50 fixed to theframe. It is clear that the type lever 41" of the highest decadeposition cannot be turned by its spring even after being released by thetrigger bar 56, since the abutment 50 detains the counterabutment 49".For any other adjustment of the type wheel 43" the counter-abutment 4would clear the abutment 50 freely. Likewise the tongue 48 of the secondgear wheel, whose type wheel is adjusted to O, is detained by the lug 49of the first type lever 41". The tongue 49 of the third gear wheel,whose type wheel is not adjusted to 0 but eg to 1 does not hit theadjacent lug 48 of the next higher decimal position, so that the typelever concerned, after being released by the trigger bar 56, is turnedforcibly and suddenly by its spring towards the platen, and the numeral1 in printed. Consequently none of the type levers 41 of lower decimalpositions can be detained by the live bridge 47.

On top of each type lever 41 a pawl 52 is pivotally mounted in anyapproved conventional manner, which resiliently engages the teeth of theaforesaid spur gear of the type wheel 43 and at any time accuratelyretains the same in its adjusted position, in order to prevent smallrotational movements of the type wheel, which could be caused uponrocking the type lever about its lowermost gear wheel 54 which wouldslightly move away from the associated toothed rack 9, whereby a largerplay in the teeth is created or generated.

In the embodiment according to FIGS. 3 and 4 there is a large limit pathavailable for the live bridge, so that Wide tolerances are permissiblefor the parts 48 and 49. The maximum permissible limit path is shorterthan in the first embodiment, since the are described by the parts 48and 49 when the type levers 41 are rocked is only about half of that ofthe types. In both cases the limit path is almost parallel to the pathcovered by the types during the printing operation, and almost of thesame order of magnitude with the latter.

It will thus be seen that the present invention provides a so-calledlive bridge or interlock between adjacent movable type carrying member'sranging from the highest order or digital position to the lowest orderwith the projections or lugs on each movable printing member supportengageable with an adjacent printing member mechanism to prevent theprinting of zeros in all digital positions higher than that typed orprinted by the selection of a printing numeral character above zero,thus preventing zeros from being printed to the left of a printednumeral character.

The calculating machine of which the present invention forms a part isillustrated as being of the ten key type having rack bars controlled bythe pins in a pin box, but obviously the printing mechanism can beassociated with other types of machines and calculators of asimilarnature.

It is to be understood that the forms of the invention herewith shownand described are to be taken as preferred embodiments thereof, and thatvarious changes in the shape, size and arrangement of parts may beresorted to without departing from the spirit of the invention or thescope of the subjoined claims.

What I claim as my invention and desire to secure by Letters Patent, is:

1. A printing device for a calculating machine comprising:

(a) a rotary platen,

(b) a plurality of printing mechanisms arranged in side by side relationand each adapted to print selectively any one of the numbers 0 to 9 on asheet placed on said platen,

(c) each one of said printing mechanisms including a rocking lever 3pivotally mounted about a fixed axle, a type carrying member 5 carryinga number of types from 0 to 9, means operatively connecting said typecarrying member with said rocking lever, a control bar movablelengthwise of its length engageable with said rocking lever for rockingsaid rocking lever to move said type carrying member and thereby aselected type on said member 5 into a position ready for printing,

((1) each printing mechanism also including a longitudinal hammer means23, rod means 25 for slidably supporting said hammer means forlengthwise movement, means 29 for operatively connecting one end of saidhammer means with said type carrying member 5 carrying said number oftypes, a projection 36 on said rocking lever for supporting the otherend of said hammer means, spring means 26 for urging said hammer meansin a direction in which the selected type on said member is caused toperform its printing movement, and means 27 operatively engaging saidhammer means for preventing said printing movement until released fromengagement with said hammer means,

(e) and abutment means 32 formed integrally with each one of said hammermeans for engagement with a counter-abutment means 34 formed integrallywith the next adjacent hammer means to prevent a lengthwise movement ofthose hammer means in a printing direction whose associated typecarrying members for all digital positions higher than the firstnon-zero digital position are adjusted to zero.

2. A printing device as claimed in claim 1, wherein said abutments areformed by struck-up lugs extending laterally from the upper marginaledges of said hammer means, said abutments being adapted to engage saidcounter-abutments formed by recesses 35 cut in one edge 34 of adjacenthammer means to provide a stop shoulder for said lugs.

References Cited by the Examiner UNITED STATES PATENTS WILLIAM B. PENN,Primary Examiner,

Mapel l0l93

1. A PAINTING DEVICE FOR A CALCULATING MACHINE COMPRISING: (A) A ROTARYPLATEN, (B) A PLURALITY OF PRINTING MECHANISMS ARRANGED IN SIDE BY SIDERELATION AND EACH ADAPTED TO PRINT SELECTIVELY ANY ONE OF THE NUMBERS"0" TO "9" ON A SHEET PLACED ON SAID PLATEN, (C) EACH ONE OF SAIDPRINTING MECHANISMS INCLUDING A ROCKING LEVER 3 PIVOTALLY MOUNTED ABOUTA FIXED AXLE, A TYPE CARRYING MEMBER 5 CARRYING A NUMBER OF TYPES FROM"0" TO "9", MEANS OPERATIVELY CONNECTING SAID TYPE CARRYING MEMBER WITHSAID ROCKING LEVER, A CONTROL BAR MOVABLE LENGTHWISE OF ITS LENGTHENGAGEABLE WITH SAID ROCKING LEVER FOR ROCKING SAID ROCKING LEVER TOMOVE SAID TYPE CARRYING MEMBER AND THEREBY A SELECTED TYPE ON SAIDMEMBER 5 INTO A POSITION READY FOR PRINTING, (D) EACH PRINTING MECHANISMALSO INCLUDING A LONGITUDINAL HAMMER MEANS 23, ROD MEANS 25 FOR SLIDABLYSUPPORTING SAID HAMMER MEANS FOR LENGTHWISE MOVEMENT, MEANS 29 FOROPERATIVELY CONNECTING ONE END OF SAID HAMMER MEANS WITH SAID TYPECARRYING MEMBER 5 CARRYING SAID NUMBER OF TYPES, A PROJECTION 36 ON SAIDROCKING LEVER FOR SUPPORTING THE OTHER END OF SAID HAMMER MEANS, SPRINGMEANS 26 FOR URGING SAID HAMMER MEANS IN A DIRECTION IN WHICH THESELECTED TYPE ON SAID MEMBER IS CAUSED TO PERFORM ITS PRINTING MOVEMENT,AND MEANS 27 OPERATIVELY ENGAGING SAID HAMMER MEANS FOR PREVENTING SAIDPRINTING MOVEMENT UNTIL RELEASED FROM ENGAGEMENT WITH SAID HAMMER MEANS,(E) AND ABUTMENT MEANS 32 FORMED INTEGRALLY WITH EACH ONE OF SAID HAMMERMEANS FOR ENGAGEMENT WITH A COUNTER-ABUTMENT MEANS 34 FORMED INTEGRALLYWITH THE NEXT ADJACENT HAMMER MEANS TO PEVENT A LENGTHWISE MOVEMENT OFTHOSE HAMMER MEANS IN A PRINTING DIRECTION WHOSE ASSOCIATED TYPECARRYING MEMBERS FOR ALL DIGITAL POSITIONS HIGHER THAN THE FIRSTNON-ZERO DIGITAL POSITION ARE ADJUSTED TO ZERO.